ABSTRACT The CHIPTS Policy Impact Core works to provide scientific bases for the identification of evidence-based HIV policies that can reduce barriers along the HIV care and prevention continua and improve the health of people living with HIV/AIDS (PLWHA) or who are at high risk for HIV. Advancing the research of existing policies on the delivery of and on the barriers to HIV treatment and prevention is vital to determining which strategies have high impact, cost effectiveness and cultural acceptability in stopping new HIV infections. Policies that reduce differences in access to and funding for combination HIV prevention services can be a powerful impact to reduce disparities in incidence across groups that differ by race/ethnicity, gender and co-morbidities, including expanded comorbidities of mental health and substance use disorders. Its three specific aims are: (1) SCIENCE: To promote applied scientific research that will inform policy-related decision making of our community and government partners, both domestically and internationally. The Core will contribute to the enactment of evidence-based policies: a) by integrating policy issues into CHIPTS research agendas on comorbidities; b) by sharing expertise in analyzing insurance claims and encounter data; c) by assisting government partners to evaluate proposed policy options; and d) by assisting local, national and international government partners to evaluate the implementation and impact of enacted policies on outcomes for PLWHA. A particular focus is to address the impact of public policies in widening or shrinking disparities related to race/ethnicity, gender, age, geographic location or comorbidities, particularly mental health and substance misuse conditions; (2) NETWORKING: To convene policy makers, HIV investigators, and community stakeholders; participate in national, state and local task forces; and provide scientific evidence for policy making. The Core disseminates policy-relevant findings to government and community partners with the goal of providing unbiased evidence for policy making, as opposed to advocacy for a predetermined position; and (3) CAPACITY BUILDING: To build the capacity of research, community, and international partners to implement and evaluate evidence-based policies. The Policy Core is led by Director Arleen Leibowitz, PhD, Co-Director Nina Harawa, PhD, MPH, and Associate Director Jennifer Gildner, MS. Core services include: integrating policy issues into CHIPTS research agendas, sharing expertise in cost-effectiveness analysis and behavioral economics, assisting government agencies in evaluating long run consequences of enacted policies, identifying problems amenable to policy solutions, disseminating to domestic and international audiences policy-relevant evidence to inform policy making, increasing ability of research and community to apply policy analytic methods for their HIV projects, mentoring junior investigators and providing evaluation of impact of core services.